(a) Field of the Invention
The present invention relates to a roller hemming system for panels of a vehicle. More particularly, the present invention relates to a roller hemming system for panels of a vehicle that is particularly adapted to hem parts such as a tail gate and a hood of the vehicle.
(b) Description of the Related Art
In a typical first stage of a vehicle manufacturing process, various vehicle panels are manufactured using a press apparatus, and the panels are transmitted to a vehicle body factory. At the vehicle body factory, the panels are assembled to form a vehicle body of a body in white (B.I.W) shape.
After the panels of the vehicle body are formed to have a predetermined shape through various press apparatus by application of pressure, the panels are cut, drilled, bent, and/or curved using press processes such as trimming, piercing, flanging, hemming, and so on.
In addition, edges of a door, a hood, a trunk, a wheel arch, or a fender of a vehicle are hemmed, and a welding surface is secured at a regional part and is welded through face welding so as to reinforce joining strength of hemming.
During a hemming process, edges of an inner panel are flanged and clinched inwardly, and a hemming sealer is sprayed into a gap formed during clinching. This hemming process is performed while the inner panel is fitted in an outer panel. At this time, the hemming sealer is heated and hardened through a painting process so that it functions as glue.
According to a conventional hemming process, after a mold corresponding to a panel is mounted at a press type device, and the outer panel and the inner panel are inserted in the mold, a press mold is moved downwardly so as to fold an end portion of the panels and join the panels.
Because an expensive mold having a shape similar to the panels must be manufactured in this process, an initial plant and equipment investment may be very large. In addition, because the size of such a press body is very big, designing the equipment layout in a factory is very difficult.
In a case of a mass-production line which produces various vehicle models, the hemming process should be performed after the molds are replaced depending on the vehicle model being produced. Therefore, much time and effort is required to replacing the molds and productivity may be deteriorated.
So as to solve such problems, a roller hemming method using a robot is mainly used. However, mass production of various vehicle models is difficult, equipment for transferring, loading, and clamping the panels is very complex, working hours are long, and the initial investment increases according to the roller hemming method.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.